jsnum.c

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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   IBM Corp.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/*
 * JS number type and wrapper class.
 */
#include "jsstddef.h"
#if defined(XP_WIN) || defined(XP_OS2)
#include <float.h>
#endif
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include "jstypes.h"
#include "jsutil.h" /* Added by JSIFY */
#include "jsapi.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsconfig.h"
#include "jsdtoa.h"
#include "jsgc.h"
#include "jsinterp.h"
#include "jsnum.h"
#include "jsobj.h"
#include "jsopcode.h"
#include "jsprf.h"
#include "jsstr.h"

static JSBool
num_isNaN(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    jsdouble x;

    if (!js_ValueToNumber(cx, argv[0], &x))
	return JS_FALSE;
    *rval = BOOLEAN_TO_JSVAL(JSDOUBLE_IS_NaN(x));
    return JS_TRUE;
}

static JSBool
num_isFinite(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    jsdouble x;

    if (!js_ValueToNumber(cx, argv[0], &x))
	return JS_FALSE;
    *rval = BOOLEAN_TO_JSVAL(JSDOUBLE_IS_FINITE(x));
    return JS_TRUE;
}

static JSBool
num_parseFloat(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    JSString *str;
    jsdouble d;
    const jschar *bp, *ep;

    str = js_ValueToString(cx, argv[0]);
    if (!str)
	return JS_FALSE;
    /* XXXbe js_strtod shouldn't require NUL termination */
    bp = js_UndependString(cx, str);
    if (!bp)
	return JS_FALSE;
    if (!js_strtod(cx, bp, &ep, &d))
	return JS_FALSE;
    if (ep == bp) {
	*rval = DOUBLE_TO_JSVAL(cx->runtime->jsNaN);
	return JS_TRUE;
    }
    return js_NewNumberValue(cx, d, rval);
}

/* See ECMA 15.1.2.2. */
static JSBool
num_parseInt(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    JSString *str;
    jsint radix;
    jsdouble d;
    const jschar *bp, *ep;

    str = js_ValueToString(cx, argv[0]);
    if (!str)
	return JS_FALSE;

    if (argc > 1) {
	if (!js_ValueToECMAInt32(cx, argv[1], &radix))
	    return JS_FALSE;
    } else
	radix = 0;

    if (radix != 0 && (radix < 2 || radix > 36)) {
	*rval = DOUBLE_TO_JSVAL(cx->runtime->jsNaN);
	return JS_TRUE;
    }
    /* XXXbe js_strtointeger shouldn't require NUL termination */
    bp = js_UndependString(cx, str);
    if (!bp)
	return JS_FALSE;
    if (!js_strtointeger(cx, bp, &ep, radix, &d))
	return JS_FALSE;
    if (ep == bp) {
	*rval = DOUBLE_TO_JSVAL(cx->runtime->jsNaN);
	return JS_TRUE;
    }
    return js_NewNumberValue(cx, d, rval);
}

const char js_Infinity_str[]   = "Infinity";
const char js_NaN_str[]        = "NaN";
const char js_isNaN_str[]      = "isNaN";
const char js_isFinite_str[]   = "isFinite";
const char js_parseFloat_str[] = "parseFloat";
const char js_parseInt_str[]   = "parseInt";

static JSFunctionSpec number_functions[] = {
    {"isNaN",           num_isNaN,              1,0,0},
    {"isFinite",        num_isFinite,           1,0,0},
    {"parseFloat",      num_parseFloat,         1,0,0},
    {"parseInt",        num_parseInt,           2,0,0},
    {0,0,0,0,0}
};

static JSClass number_class = {
    "Number",
    JSCLASS_HAS_PRIVATE,
    JS_PropertyStub,  JS_PropertyStub,  JS_PropertyStub,  JS_PropertyStub,
    JS_EnumerateStub, JS_ResolveStub,   JS_ConvertStub,   JS_FinalizeStub,
    JSCLASS_NO_OPTIONAL_MEMBERS
};

static JSBool
Number(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    jsdouble d;
    jsval v;

    if (argc != 0) {
	if (!js_ValueToNumber(cx, argv[0], &d))
	    return JS_FALSE;
    } else {
	d = 0.0;
    }
    if (!js_NewNumberValue(cx, d, &v))
	return JS_FALSE;
    if (!(cx->fp->flags & JSFRAME_CONSTRUCTING)) {
	*rval = v;
	return JS_TRUE;
    }
    OBJ_SET_SLOT(cx, obj, JSSLOT_PRIVATE, v);
    return JS_TRUE;
}

#if JS_HAS_TOSOURCE
static JSBool
num_toSource(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    jsval v;
    jsdouble d;
    char numBuf[DTOSTR_STANDARD_BUFFER_SIZE], *numStr;
    char buf[64];
    JSString *str;

    if (!JS_InstanceOf(cx, obj, &number_class, argv))
	return JS_FALSE;
    v = OBJ_GET_SLOT(cx, obj, JSSLOT_PRIVATE);
    JS_ASSERT(JSVAL_IS_NUMBER(v));
    d = JSVAL_IS_INT(v) ? (jsdouble)JSVAL_TO_INT(v) : *JSVAL_TO_DOUBLE(v);
    numStr = JS_dtostr(numBuf, sizeof numBuf, DTOSTR_STANDARD, 0, d);
    if (!numStr) {
	JS_ReportOutOfMemory(cx);
	return JS_FALSE;
    }
    JS_snprintf(buf, sizeof buf, "(new %s(%s))", number_class.name, numStr);
    str = JS_NewStringCopyZ(cx, buf);
    if (!str)
	return JS_FALSE;
    *rval = STRING_TO_JSVAL(str);
    return JS_TRUE;
}
#endif

/* The buf must be big enough for MIN_INT to fit including '-' and '\0'. */
static char *
IntToString(jsint i, char *buf, size_t bufSize)
{
    char *cp;
    jsuint u;
    
    u = (i < 0) ? -i : i;

    cp = buf + bufSize; /* one past last buffer cell */
    *--cp = '\0';       /* null terminate the string to be */
    
    /*
     * Build the string from behind. We use multiply and subtraction
     * instead of modulus because that's much faster.
     */
    do {
        jsuint newu = u / 10;
        *--cp = (char)(u - newu * 10) + '0';
        u = newu;
    } while (u != 0);
    
    if (i < 0)
        *--cp = '-';

    return cp;
}

static JSBool
num_toString(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    jsval v;
    jsdouble d;
    jsint base;
    JSString *str;

    if (!JS_InstanceOf(cx, obj, &number_class, argv))
	return JS_FALSE;
    v = OBJ_GET_SLOT(cx, obj, JSSLOT_PRIVATE);
    JS_ASSERT(JSVAL_IS_NUMBER(v));
    d = JSVAL_IS_INT(v) ? (jsdouble)JSVAL_TO_INT(v) : *JSVAL_TO_DOUBLE(v);
    base = 10;
    if (argc != 0) {
	if (!js_ValueToECMAInt32(cx, argv[0], &base))
	    return JS_FALSE;
	if (base < 2 || base > 36) {
	    char numBuf[12];
	    char *numStr = IntToString(base, numBuf, sizeof numBuf);
	    JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_BAD_RADIX,
	    			 numStr);
	    return JS_FALSE;
	}
    }
    if (base == 10)
	str = js_NumberToString(cx, d);
    else {
	char *dStr = JS_dtobasestr(base, d);
	if (!dStr) {
	    JS_ReportOutOfMemory(cx);
	    return JS_FALSE;
	}
	str = JS_NewStringCopyZ(cx, dStr);
	free(dStr);
    }
    if (!str)
	return JS_FALSE;
    *rval = STRING_TO_JSVAL(str);
    return JS_TRUE;
}

static JSBool
num_toLocaleString(JSContext *cx, JSObject *obj, uintN argc,
                   jsval *argv, jsval *rval)
{
/*
 *  For now, forcibly ignore the first (or any) argument and return toString().
 *  ECMA allows this, although it doesn't 'encourage it'.
 *  [The first argument is being reserved by ECMA and we don't want it confused
 *  with a radix]
 */
    return num_toString(cx, obj, 0, argv, rval);
}

static JSBool
num_valueOf(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    if (!JS_InstanceOf(cx, obj, &number_class, argv))
	return JS_FALSE;
    *rval = OBJ_GET_SLOT(cx, obj, JSSLOT_PRIVATE);
    return JS_TRUE;
}


#if JS_HAS_NUMBER_FORMATS
#define MAX_PRECISION 100

static JSBool
num_to(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval, JSDToStrMode zeroArgMode,
       JSDToStrMode oneArgMode, jsint precisionMin, jsint precisionMax, jsint precisionOffset)
{
    jsval v;
    jsdouble d, precision;
    JSString *str;
    char buf[DTOSTR_VARIABLE_BUFFER_SIZE(MAX_PRECISION+1)], *numStr; /* Use MAX_PRECISION+1 because precisionOffset can be 1 */

    if (!JS_InstanceOf(cx, obj, &number_class, argv))
	return JS_FALSE;
    v = OBJ_GET_SLOT(cx, obj, JSSLOT_PRIVATE);
    JS_ASSERT(JSVAL_IS_NUMBER(v));
    d = JSVAL_IS_INT(v) ? (jsdouble)JSVAL_TO_INT(v) : *JSVAL_TO_DOUBLE(v);

    if (JSVAL_IS_VOID(argv[0])) {
	precision = 0.0;
	oneArgMode = zeroArgMode;
    } else {
	if (!js_ValueToNumber(cx, argv[0], &precision))
	    return JS_FALSE;
	precision = js_DoubleToInteger(precision);
        if (precision < precisionMin || precision > precisionMax) {
            numStr = JS_dtostr(buf, sizeof buf, DTOSTR_STANDARD, 0, precision);
            if (!numStr)
                JS_ReportOutOfMemory(cx);
            else
                JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_PRECISION_RANGE, numStr);
            return JS_FALSE;
        }
    }

    numStr = JS_dtostr(buf, sizeof buf, oneArgMode, (jsint)precision + precisionOffset, d);
    if (!numStr) {
	JS_ReportOutOfMemory(cx);
	return JS_FALSE;
    }
    str = JS_NewStringCopyZ(cx, numStr);
    if (!str)
	return JS_FALSE;
    *rval = STRING_TO_JSVAL(str);
    return JS_TRUE;
}

static JSBool
num_toFixed(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    /* We allow a larger range of precision than ECMA requires; this is permitted by ECMA. */
    return num_to(cx, obj, argc, argv, rval, DTOSTR_FIXED, DTOSTR_FIXED, -20, MAX_PRECISION, 0);
}

static JSBool
num_toExponential(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    /* We allow a larger range of precision than ECMA requires; this is permitted by ECMA. */
    return num_to(cx, obj, argc, argv, rval, DTOSTR_STANDARD_EXPONENTIAL, DTOSTR_EXPONENTIAL, 0, MAX_PRECISION, 1);
}

static JSBool
num_toPrecision(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    /* We allow a larger range of precision than ECMA requires; this is permitted by ECMA. */
    return num_to(cx, obj, argc, argv, rval, DTOSTR_STANDARD, DTOSTR_PRECISION, 1, MAX_PRECISION, 0);
}
#endif /* JS_HAS_NUMBER_FORMATS */


static JSFunctionSpec number_methods[] = {
#if JS_HAS_TOSOURCE
    {js_toSource_str,       num_toSource,       0,0,0},
#endif
    {js_toString_str,	    num_toString,       0,0,0},
    {js_toLocaleString_str, num_toLocaleString, 0,0,0},
    {js_valueOf_str,	    num_valueOf,        0,0,0},
#if JS_HAS_NUMBER_FORMATS
    {"toFixed",             num_toFixed,        1,0,0},
    {"toExponential",       num_toExponential,  1,0,0},
    {"toPrecision",         num_toPrecision,    1,0,0},
#endif
    {0,0,0,0,0}
};

/* NB: Keep this in synch with number_constants[]. */
enum nc_slot {
    NC_NaN,
    NC_POSITIVE_INFINITY,
    NC_NEGATIVE_INFINITY,
    NC_MAX_VALUE,
    NC_MIN_VALUE,
    NC_LIMIT
};

/*
 * Some to most C compilers forbid spelling these at compile time, or barf
 * if you try, so all but MAX_VALUE are set up by js_InitRuntimeNumberState
 * using union jsdpun.
 */
static JSConstDoubleSpec number_constants[] = {
    {0,                         js_NaN_str,          0,{0,0,0}},
    {0,                         "POSITIVE_INFINITY", 0,{0,0,0}},
    {0,                         "NEGATIVE_INFINITY", 0,{0,0,0}},
    {1.7976931348623157E+308,   "MAX_VALUE",         0,{0,0,0}},
    {0,                         "MIN_VALUE",         0,{0,0,0}},
    {0,0,0,{0,0,0}}
};

static jsdouble NaN;


#if defined XP_WIN &&                                                         \
    !defined __MWERKS__ &&                                                    \
    (defined _M_IX86 ||                                                       \
     (defined __GNUC__ && !defined __MINGW32__))

/*
 * Set the exception mask to mask all exceptions and set the FPU precision
 * to 53 bit mantissa.
 * On Alpha platform this is handled via Compiler option.
 */
#define FIX_FPU() _control87(MCW_EM | PC_53, MCW_EM | MCW_PC)

#else

#define FIX_FPU() ((void)0)

#endif

JSBool
js_InitRuntimeNumberState(JSContext *cx)
{
    JSRuntime *rt;
    jsdpun u;

    rt = cx->runtime;
    JS_ASSERT(!rt->jsNaN);

    FIX_FPU();

    u.s.hi = JSDOUBLE_HI32_EXPMASK | JSDOUBLE_HI32_MANTMASK;
    u.s.lo = 0xffffffff;
    number_constants[NC_NaN].dval = NaN = u.d;
    rt->jsNaN = js_NewDouble(cx, NaN);
    if (!rt->jsNaN || !js_LockGCThing(cx, rt->jsNaN))
        return JS_FALSE;

    u.s.hi = JSDOUBLE_HI32_EXPMASK;
    u.s.lo = 0x00000000;
    number_constants[NC_POSITIVE_INFINITY].dval = u.d;
    rt->jsPositiveInfinity = js_NewDouble(cx, u.d);
    if (!rt->jsPositiveInfinity ||
        !js_LockGCThing(cx, rt->jsPositiveInfinity)) {
        return JS_FALSE;
    }

    u.s.hi = JSDOUBLE_HI32_SIGNBIT | JSDOUBLE_HI32_EXPMASK;
    u.s.lo = 0x00000000;
    number_constants[NC_NEGATIVE_INFINITY].dval = u.d;
    rt->jsNegativeInfinity = js_NewDouble(cx, u.d);
    if (!rt->jsNegativeInfinity ||
        !js_LockGCThing(cx, rt->jsNegativeInfinity)) {
        return JS_FALSE;
    }

    u.s.hi = 0;
    u.s.lo = 1;
    number_constants[NC_MIN_VALUE].dval = u.d;

    return JS_TRUE;
}

void
js_FinishRuntimeNumberState(JSContext *cx)
{
    JSRuntime *rt = cx->runtime;

    js_UnlockGCThingRT(rt, rt->jsNaN);
    js_UnlockGCThingRT(rt, rt->jsNegativeInfinity);
    js_UnlockGCThingRT(rt, rt->jsPositiveInfinity);

    rt->jsNaN = NULL;
    rt->jsNegativeInfinity = NULL;
    rt->jsPositiveInfinity = NULL;
}

JSObject *
js_InitNumberClass(JSContext *cx, JSObject *obj)
{
    JSObject *proto, *ctor;
    JSRuntime *rt;

    /* XXX must do at least once per new thread, so do it per JSContext... */
    FIX_FPU();

    if (!JS_DefineFunctions(cx, obj, number_functions))
	return NULL;

    proto = JS_InitClass(cx, obj, NULL, &number_class, Number, 1,
			 NULL, number_methods, NULL, NULL);
    if (!proto || !(ctor = JS_GetConstructor(cx, proto)))
	return NULL;
    OBJ_SET_SLOT(cx, proto, JSSLOT_PRIVATE, JSVAL_ZERO);
    if (!JS_DefineConstDoubles(cx, ctor, number_constants))
	return NULL;

    /* ECMA 15.1.1.1 */
    rt = cx->runtime;
    if (!JS_DefineProperty(cx, obj, js_NaN_str, DOUBLE_TO_JSVAL(rt->jsNaN),
			   NULL, NULL, JSPROP_PERMANENT)) {
	return NULL;
    }

    /* ECMA 15.1.1.2 */
    if (!JS_DefineProperty(cx, obj, js_Infinity_str,
			   DOUBLE_TO_JSVAL(rt->jsPositiveInfinity),